1. Field of the Invention
This invention relates in general to the field of orthopedic apparatus and in particular to the field of orthopedic therapeutic foot supports or those now commonly called orthotics.
2. Description of the Prior Art
In general, the primary purpose of orthotics is to limit the complex motions of excessive and/or ill-timed pronation and to a lesser extent, supination. Simplified, pronation is the flattening or rolling inward of the foot as the foot strikes the ground such as when walking, running, as the foot is pushing down on the pedal of a bicycle, or as the foot is moving down when a skier is negotiating a bump on the ski slopes. A weak foot will experience excessive pronation during such mild activities as walking or even standing; while a strong foot will experience excessive pronation during vigorous sports activities. Supination, on the other hand, is the rolling outward of the foot. When either or both of these motions become excessive or ill-timed, destructive changes to the foot, ankle, legs, and knees can occur.
The present state of the art in orthotic devices may be broken down into two basic categories: rigid and semiflexible.
Rigid orthotics rely on their own strength and rigidity in controlling the movements of a foot. Early rigid orthotics were made from sheet steel and later aluminum, which was hammered into shape to conform to the patient's foot. Laminated fiberglass was also used somewhat later by being laid up against a cast of a foot and then covered with a material such as leather. The latest rigid type of conventional orthotic devices are generally manufactured from an acrylic thermoplastic material. Such orthotics can be prefabricated in various shoe and arch sizes or custom made to plaster impressions of a foot. Acrylic thermoplastic materials have been used because of their ability to be shaped or molded using sheet stock as the raw material and because of their strength. Such materials are, however, hard and brittle. These latter two traits have resulted in wearer discomfort and sometimes breakage. Attempts to overcome the breakage problem included using a thicker sheet of material and/or laminating a thickness of fiberglass to the molded orthotic. Neither of these solutions has been satisfactory because of the increased thickness of the resulting orthotic which undesirably raises the foot within the shoe containing the orthotic device.
When it is necessary to correct or slightly adjust the control afforded by a rigid orthotic, a device known as a post is used. A post adds a small amount of material or a pad, which often comprises a dental acrylic material, which is bonded to the underside of the orthotic device where it contacts the shoe. The brittle nature of commonly used dental acrylic further affects the breakage problem noted above in that the posts have been known to break in advance of the orthotic. This breakage results in an even shorter orthotic device life span. Also, posts have been known to separate from orthotic devices because of the difficulties involved in bonding the two materials which often results in incomplete bonding.
Semiflexible orthotics were first constructed of leather having an arch filled with a semicompressible material such as cork, sponge, or other like material, which contacted the arch of the shoe and thereby provided the necessary support. More recent designs of the semiflexible type were made from thermoplastics such as polypropylene or polyethylene. Commonly, the more recent semiflexible type of orthotic device had a uniform thickness in the range of 3.0 to 6.0 mm. As with the prior art rigid type, the semiflexible devices are also posted for purposes of correction and control. The material used for posting is of a dynamic or semicompressible type because of the flexible nature of the plate of the orthotic. There is, in the prior art, another version of the semiflexible orthotic, comprising a thin plate of thermoplastic (1.0-2.5 mm) which is supported by a semicompressible material similar to the leather types, relying again upon cushioned arch support provided by contact with the shoe.
The rigid type of orthotic, inherently affords the most positive control and is, therefore, preferred in many cases. The semiflexible orthotic devices, however, have the ability to provide quite satisfactory control in many cases where rigid control is not possible or desirable as often is the case when treating sports or geriatric patients. In the case of sports patients, especially casual sports patients, it should be noted that semiflexible devices are used not so much for their ability to flex but rather for their breakage resistance.
In accordance with the above, new and different rigid orthotic devices are desired which provide the material softness of the semiflexible type in combination with the basic rigidity of the rigid type of orthotic, but without the breakage associated with the latter type and without an attendant increase in overall thickness, weight, or bulk. Also, new and different semiflexible orthotic devices are desired which incorporate the above-stated features and allow for preselected areas of support and flexibility to provide greater latitude and more precision in their application.
Accordingly, an object of the present invention is to provide a rigid orthotic device which allows the use of a traditionally semiflexible material but which provides the rigidity of traditionally rigid orthotic devices.
Another object of the present invention is to provide an orthotic device, rigid or semiflexible, which is capable of being reinforced in preselected locations by a preselected amount.
Another object of the present invention is to provide a rigid orthotic device which has a relatively thin heel section to provide an enhanced fit and effectively lower the device within a shoe.
Another object of the present invention is to provide a rigid orthotic device which provides positive foot control but is flexible in noncontrol locations to result in a better fit within a shoe and provides a foot with a better and more comfortable fit.
Another object of the present invention is to provide a rigid orthotic device which includes integral front and rear posts.
Another object of the present invention is to provide a rigid orthotic device with increased resistance to breaking while providing desired rigidity.
Another object of the present invention is to provide a rigid orthotic device which allows for integral correction, adjustment, and variability in flexibility after the device has been dispensed.
Another object of the present invention is to provide a semiflexible orthotic device of reduced thickness and weight.
Another object of the present invention is to provide a semiflexible orthotic device which allows for selective areas of flexibility and selective areas of control.
Another object of the present invention is to provide a semiflexible orthotic device which provides improved foot control.
The above-stated objects and inherent advantages as well as those not stated but implied, in accordance with a fair reading and interpretation of this specification, the claims and drawings are intended to be included within the present invention as claimed and described.